The present invention relates to a wheel, in particular for a bicycle, and preferably for a motorcycle, with a hub, a rim, and spokes or a disk extending between the hub and the rim. The wheel is vertically divided, and each of the two wheel parts comprises as integral parts one half of each of the hub, the spokes or the disk, and the rim.
Wheels of the above-described kind have been known for a long time in a large variety of types. For example, reference may be made to WO 96/08383. The wheel disclosed in WO 96/08383 is a wheel for bicycles, wherein differently designed and constructed wheel parts are joined by gluing. The parts of this known wheel as a whole are glued together, i.e., both in the region of the hub and the rim, as well as in the region of the spokes. In other words, the wheel parts are joined by gluing in all boundary or butt joints, so that the two wheel parts form together a homogeneous wheel per se.
The wheel as known from WO 96/08383, wherein the wheel parts are joined by gluing, may be suitable for use in bicycles. However, based on its all-around glued joints, this wheel exhibits an only limited strength or torsional resistance, which is in any event inadequate for use in a motorcycle. Furthermore, in the case of the known wheel, it is necessary to manufacture different wheel halves because of the selected joining technique and engagement of the wheel halves. This increases the manufacturing expenditure and, thus, the production costs.
It is an object of the present invention to design and construct and further develop a wheel that in some ways resembles the above-described wheel, and which is easy and yet cost-favorable to make, while ensuring the stability and rigidity required for use in a motorcycle.
The above and other objects and advantages of the invention are achieved by the provision of a wheel having two wheel parts, namely first and second wheel parts. The first wheel part comprises a first hub portion, a first rim portion extending around the first hub portion, and first structure, such as spoke members, connected between the first hub portion and the first rim portion. Likewise, the second wheel part comprises a second hub portion, a second rim portion extending around the second hub portion, and second structure, such as spoke members, connected between the second hub portion and the second rim portion. The first and second rim portions are connected and together function as a rim of the wheel. Likewise, the first and second hub portions are connected and together function as a hub of the wheel. The two wheel parts are interconnected exclusively in the region of the hub and rim.
It has been recognized by the present invention that for obtaining the necessary stability and strength or rigidity of the wheel, it will totally suffice when the two wheel parts are joined together exclusively in the region of the hub and the rim, and not in the region of the spokes. Such a construction, according to the invention, is based on the thought that it is possible to save material in the region of the spokes. Accordingly, in accordance with one aspect of the present invention, it is not necessary to join the two wheel parts in the region of the spokes. Instead, for purposes of saving material and reducing the weight, the region between the spoke halves is left open because this region contributes only little to the strength or rigidity of the wheel.
In accordance with another aspect of the invention, the two wheel parts can be made at least largely identical (i.e., substantially identical), when a connection is provided only in the region of the hub and the rim. The two wheel parts can be made initially identical such as by die casting the two wheel parts in the same die. Thereafter, the joining regions of the hub and rim can be machined or reworked so that it is possible to apply different joining techniques, as will be described further below.
As mentioned above, once the two wheel parts are joined they together form the hub and the rim of the resulting wheel. In accordance with another aspect of the invention, the wheel parts comprise each an inward extending joining region, and those joining regions engage each other to form the hub. In accordance with one example, each joining region is an inward extending, substantially cylindrical section, with the cylindrical section of one wheel part engaging over the cylindrical section of the other wheel part. In accordance with another example, the cylindrical section of one wheel part engages the cylindrical section of the other wheel part, such as in a recess thereof. In this instance, a kind of tongue and groove joint exists between the two wheel parts.
The two joining regions forming the hub can be interconnected in a force-locking and/or formfitting and/or material-engaging manner. For example, the joining regions of the wheel parts that form the hub can be slipped into or onto each other. Likewise, the joining regions of the wheel parts which form the hub can be pressed, screwed, riveted and/or glued together. A combination of the foregoing joining techniques can be used. Thus, besides gluing together the joining regions, they can additionally be screwed or riveted together.
The above-described connections can also be used in the region of the wheel rim. Accordingly, the wheel parts each include a joining region, which is preferably peripherally arranged, and those joining regions are joined to form the wheel rim. For example, the joining regions of the rim can abut and connect to each other in a formfitting and/or force-locking and/or material-engaging manner. As an additional example, the joining regions can be welded together with a notch, preferably a peripheral notch, being provided in the region of the butt joints for receiving a weld seam. To this extent, the weld seam can be placed into the notch and leveled outside the notch toward the smooth surface of the rim. Likewise, it is acceptable to glue, screw, and/or rivet together the joining regions of the rim, and these different joining techniques can be combined.
Between the joining regions of the wheel parts a sealing means can be provided for purposes of excluding air, such as for excluding the passage of air between the joining regions of the rim. More specifically, a peripheral seal can extend between the butt joints of the joining regions. To this end, the joining regions can comprise in their oppositely directed front surfaces corresponding recesses or grooves for receiving the sealing means. More specifically, a peripheral O-ring can be inserted as a compression seal. Another acceptable sealing means for excluding air can be a weld seam, such as the above-mentioned weld seam, extending around and connecting the joining regions of the rim.
In accordance with another aspect of the invention, in the furtherance of advantageously reducing weight, the spoke halves of the wheel parts abut at their ends, i.e., in the region of the hub and the rim, and otherwise are spaced at least slightly from one another. The spacing between the spoke halves can decrease from the hub toward the rim. The region between the spoke halves can be a hollow space, which permits reducing the weight to an extraordinary extent. However, the region between the spoke halves can also be filled. The filling material can be a lightweight and anticorrosive material, such as plastic.
In accordance with another aspect of the invention, the region between the spoke halves is filled exclusively in the edge zone, preferably in a sealing manner against humidity and dirt. Likewise, to this end, plastic can be used as a quasi sealing insert.
In order to increase stability while reducing the amount of material that is used, the spoke halves can have U-shaped or dish-shaped cross sections. To increase stability, the spoke halves can be provided with reinforcements extending in the longitudinal direction. To this extent, the spoke halves can be constructed with a W-shaped cross section, with the rigidity being increased by the longitudinally extending center bar.
In accordance with another aspect of the invention, the opposite spoke halves together have an approximately circular cross section, thereby favoring the rigidity of each spoke quite considerably. Likewise, the opposite spoke halves can have an approximately oval cross section.
In accordance with another aspect of the invention, the wheel is light weight because the wheel halves are made of aluminum or an aluminum alloy. Likewise, the wheel halves can be made of magnesium or a magnesium alloy. To increase strength, fiber-reinforced aluminum or magnesium materials can be used. The wheel halves can also be made of a carbon-fiber reinforced material. In this instance, plastic with embedded carbon fibers can also be used.
When the wheel halves are made of aluminum, magnesium, or corresponding alloys, the wheel halves can be produced by the die casting method. Before joining the wheel halves, a subsequent machining of the wheel halves can be performed, in particular to provide a suitable joining region for forming the hub and the rim.